package edu.cs.iit.cs495;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;

public class WordCountMR {
	public static class Map extends Mapper<LongWritable, Text, Text, IntWritable> {
		private final static IntWritable one = new IntWritable(1);
		private Text word = new Text();

		public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
			String line = value.toString();
			line = line.replaceAll("(\\s|^)\\p{Punct}++(\\s|$)" , "$1$2");
			line = line.replaceAll("(\\w+)\\p{Punct}++(\\s|$)" , "$1$2");
			line = line.replaceAll("(\\s|^)\\p{Punct}++(\\w+)" , "$1$2");
			String[] tmp = line.split("[^\\p{Graph}]");
			for(int j=0;j<tmp.length; j++ ){
				if(!tmp[j].isEmpty())
					word.set(tmp[j]);
					context.write(word, one);
			}
		}
	} 

	public static class Reduce extends Reducer<Text, IntWritable, Text, IntWritable> {

		public void reduce(Text key, Iterable<IntWritable> values, Context context) 
				throws IOException, InterruptedException {
			int sum = 0;
			for (IntWritable val : values) {
				sum += val.get();
			}
			context.write(key, new IntWritable(sum));
		}
	}

	public static void main(String[] args) throws Exception {
		Configuration conf = new Configuration();

		Job job = new Job(conf, "wordcount");
		job.setJarByClass(WordCountMR.class);
		
		job.setOutputKeyClass(Text.class);
		job.setOutputValueClass(IntWritable.class);
		
		
		job.setMapperClass(Map.class);
		job.setReducerClass(Reduce.class);

		job.setInputFormatClass(TextInputFormat.class);
		job.setOutputFormatClass(TextOutputFormat.class);

	
		FileInputFormat.addInputPath(job, new Path(args[0]));
		FileOutputFormat.setOutputPath(job, new Path(args[1]));
		
	
		Calendar begin = Calendar.getInstance();
		job.waitForCompletion(true);
		Calendar end = Calendar.getInstance();
		long time = end.getTimeInMillis() - begin.getTimeInMillis();
		System.out.println("Run time : "+(float)time/(float)1000+ "sec");
	}
}
